Electric soldering-iron.



No. 870,779. l PATENTED NOV. 12, 1907.

' W. G. HARTWIG.

ELECTRIC SOLDERING IRON.

APPLICATION FILED MAE. 21. 1907.

UNITED STATES PATENT OFFICE.

WILLIAMGEOBGE HARTWIG, OF CHICAGO, ILLINOIS.

ELECTRIC SOLDERING-IRON.

Nmsvopve.

Specification of Letters Patent,

-Patented Nov. 12, 190'?.

Application nea mmh 21.1907. ser-in No. 5163.547.

. county of Cook and State o Illinois, have invented cer" tain new and useiul Improvements in Electric Soldering-Irons, of which I do declare the following to bea full, clear, and exact description, reference being had to the accompanying drawing, forming part oi this specification.

Figure I is a view in central longitudinal section through an rkelectric soldering iron. Fig. 2 is a View in transverse section on line 2-2 of Fig. I. Fig. 3 isa view soldering iron to which the heat may be mest effectively in transverse section on line 3 3 of Fig. I, 2 and 3 being upon an enlarged scale'.

The present invention has for its object to provide an electric soldering iron in which the heat geneiated Within the head oi the iron shall be applied at the most effective point and the invention consists in the vieatures oi improvement hereinafter described, illustrated in the accompanying drawing and more particularly pointed out in the claims at the end of this specification. A designates the copper head o the soldering iron that is bored out or chambered as shown. The outer end portion oi the chamber o the head A is interiorly screw-threaded to receive the exterior screw-thread b that is formed upon one end oi the hollow stem B. The

' opposite end of the stem B has fitted thereto a tubular handle oi suitable material. Within the chamber of the head A is set an insulatingsleeve D of porcelain or other suitable insulating material and within this in sulating sleeve D is placed a solid body of carborundum crystal E that will be pressed against the head A by means oi a plunger F that is carried within the sleeve B. The plunger F has a reduced stem f passing through the insulating sleeve D and a shoulder or ofisetj'/ on the plunger F serves to limit the extent oi the movement of the sleeve B towards the head A and thus guards against any danger o-short-circ uiting by reason of the contact of the end o i the plunger with the head A. The outer end of-the plunger F is formed with a stemf2 that is encircled by a coilfsprin'g that serves to force the plunger F towards the head A.V -The sternfz of the plunger F passes through an insulating sleeve H that is held within the outer end of the tub ularhandle C, thisv insulatingsleeve H being preerably formed with a flange h that is cut away at one side to receive the terminal extension b2 at the outer end of the sleeve B. To this terminal extension 'b2 is connected one oi the conductor wires K and) the other conductor wire K of the circuit is connected to the outer end or' the plunger stem f 2. The insulating sleeve D serving as it does to 'hold the high resistance .material E out o contact with the head A ofthe solderling iron except at the end of the sleeve insures the ap-` plication of the heat due to the passageV of current' through the high resistance material to that part of the used.' The insulating sleeve D and the.insulating sleeve H serve also to hold the plunger out oi Contact with the sleeve B and thus prevent the short-circuiting ot the current between such parts. The pll'rnger efiectively serves to insure a constant contact between the high resistance material and the head A of the soldering iron.

readily understood.l Current will pass by one of the conductor wires K to the sleeve B and through the head A and high resistance material E to the plunger F and thence to the other conductor wire K. When it is desired to inserta new piece oicarborundum within the chamber of the head A, the head can be unscrewed from the sleeve D or such purpose.

It is manifest that the precise details o construction above set out may be varied without departure from the spirit oi the invention.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is'.-

1. An electrically heated tool comprising a ciiarnliered head, a tubular sleeve connected to said head and provided with'a handle, a sleeve of .insulating'material within said hcad,.a body of high resistance material within said insulating sleeve, and a plunger passing through said insulating sleeve and serving to force said body of high resistance material against said head, said plunger' being provided with an oiset part to limit the extent of its movement.

' 2. An electric soldering iron comprising a chambered soldering head, a tubular' stem connected to said head and provided with a handle, an operrended insulating sleeve arranged within said chamber-ed soldering head, a body of high resistance material within said insulating sleeve, a metallic conductor passing `through said insulating sleeve and means for causing said conductor to normally hold said body of high ,resistance material against said soldering head. y

3. An electric solder-ing iron comprising a. chambered soldering head, a tubular sleeve connected to said soldering head and providedl with a handle, 'an open-ended insulating sleeve within said tubular sleeve and extending into the chamber' of the soldering head, a body of high resistance materiali within said insulating sleeve and hearing against said soldering head, an insulating sleeve within the outer' end of said tubular sleeve, a metallic plunger arranged within said. insulating sleeves and means for causing said plunger te force said body' of Ahigh resistance material against thc soldering head.I

4. A sfnider'ing iron comprising :risoldcring head, a tubular sleeve connected to 'said soldering head, a sleeve of insulating material wlthnsaid tubular sleeve, high resistance material within said insulating sleeve and bearing against the soldering head and a spring-actuated plunger engaging said high resistance material.

5. An electric soldering iron comprising' {1,soidering head constituting one of the terminals of the electric circuit, a'body of carborundum crystal bearing against said soldering head,` an insulating Ysleeve surrounding said body of carborundum anda metallic conductor engaging said body of carberundum and constituting the other terminai of said circuit.

6. An electric soldering iron comprising a. chambered soldering head, a tubular sleeve screw-threaded to said The operation of my improved soldering iron will. be N soldern'f.,r head, an open-ended insulating sleeve within said tubular sleeve and within the chamber of the soldering head, a body of high resistance material within said insulating sleeve, armetaliic plunger bearing against said body of high resistance material and a spring for holding said plunger into contact` with said body of high resistance material and for forcing said body against the soldering head.

7. An electric soldering iron comprising .a soldering head, a stem connected to said soldering head, a tubular insulating sleeve, a body o! high resistance material within said insulating s1eeve.an d.a spring-actuated plunger bearing against saidbody of high resistance 'material and having a stop or shoulder to limit its movement.

8. vAn electric soldering iron comprising a soldering 15 head, a tubular stem for said solderingl head, a body o1!y 

